This invention relates to machine tools and, more particularly, to steady rests adapted for use in machining operations.
Steady rests have been used for many years in connection with machining operations. They typically employ three hydraulically or pneumatically operated finger rollers which are adapted to concentrically support a shaft-like workpiece to provide evenly distributed support for it. The steady rest resists the tendency of the machine tool to throw the workpiece off center during machining by turning, grinding or the like. Exemplary steady rests are shown in U.S. Pat. Nos. 3,234,829 and 3,320,839 to Dinsmore, U.S. Pat. No. 2,547,529 to Lichtenberg; and U.S. Pat. No. 2,160,378 to Balsiger.
In the conventional steady rest in which the fingers are equally spaced about the workpiece, most commonly used tools must be spaced off center with respect to the steady rest since interference would result if the tool was located diametrically opposite the fingers. Accordingly, even in the best steady rest there still remains a tendency for the workpiece to be moved out of alignment by the forces acting upon it from the machine tool. In such instances uniform precision machining operations along the length of the workpiece are difficult to obtain.